Three people have been taken to hospital with smoke inhalation and residents have been evacuated as the West Melton fire threatens homes.
The fire is now contained but two helicopters and 40 firefighters remain active on site, Fire and Emergency New Zealand said.
The blaze is centred around Weedons Ross Rd area. It began on a farm at around 3pm.
Some 15 firefighters will remain on site overnight.
Two houses have already been saved. One escaped with charring to its eaves.
The homeowner was rescued by police. She was been taken to hospital with suspected smoke inhalation.
A St John spokesman said three people had been taken to hospital in relation to the fire.
One was rushed to Christchurch Hospital in a serious condition, believed to be related to smoke inhalation. Two others with minor conditions were also hospitalised, the spokesman said.
Residents who have been evacuated from the farms and lifestyle blocks have fled with pets, clothes and prized possessions.
Locals also helped rescue horses from a property ablaze.
Matt Smith, who lives across the road from the blaze, says locals shut Weedons Ross Rd and shifted the horses across to another paddock and safety. Three were stallions never handled before.
"We've been lucky," Smith said.
However the blaze is far from under control.
Heavy northerly winds are fanning it as the temperature remains above 30C.
There are fears it could spread and threaten a new subdivision.
A welfare centre set up in West Melton at the West Melton Community Centre had closed, but would be reactivated if needed.
Smith has a caravan loaded up and hooked to his car ready to flee. His power went off at 3.09pm as the fire engulfed a power pole.
The fire has come within metres of the road. Locals with buckets are dampening hot spots.
A drop in wind has helped save properties and helped fire crews get a foothold on the blaze, locals say.